Validity of the I-FEED score for postoperative gastrointestinal function in patients undergoing colorectal surgery

Postoperative ileus (POI) is common after gastrointestinal surgery and is associated with significant morbidity and costs. However, POI is poorly defined. The I-FEED score is a novel outcome measure for POI, developed by expert consensus. It contains five elements (intake, response to nausea treatment, emesis, exam, and duration, each scored with 0, 1, or 3 points) and classifies patients into normal, postoperative gastrointestinal intolerance (POGI), and postoperative gastrointestinal dysfunction (POGD). However, it has not yet been validated in a clinical context. The objective was to provide validity evidence for the I-FEED score to measure the construct of POI in patients undergoing colorectal surgery.

Data previously collected from a clinical trial investigating the impact of different perioperative fluid management strategies on primary POI in patients undergoing elective laparoscopic colectomy (2013-2015) were analyzed. Patients were managed by a longstanding Enhanced Recovery program (expected length of stay (LOS): 3 days). Daily I-FEED scores were generated (normal 0-2, POGI 3-5, POGD 6+ points) up to hospital discharge or postoperative day 7. Validity was assessed by testing the hypotheses that I-FEED score was higher (1) in patients with longer time to GI3 (tolerating diet + flatus/bowel movement), (2) with longer LOS (> 3 days vs shorter), (3) in patients with complications vs without, (4) in patients with poorer recovery (measured by Quality of Recovery-9 questionnaire).

A total of 128 patients were included for analysis (mean age 61.7 years (SD 15.2), 57% male, 71% malignancy, and 39.1% rectal resection). Median LOS was 4 days [IQR3-5], and 32% experienced postoperative in-hospital morbidity. Overall, 48% of patients were categorized as normal, 22% POGI, and 30% POGD. The data supported all 4 hypotheses.

This study contributes preliminary validity evidence for the I-FEED score as a measure for POI after colorectal surgery.